Shield advancing machine

Abstract

A shield advancing machine, comprising cutting tools (15) rotatably supported on cantilever arms (13, 14) being rotatable around an axis approximately extending in advancing direction and being swivellable in transverse direction to this axis, has a carrier (4) which is guided and supported in axial direction of the shield (1). A rotation drive (22, 33) for a rest (9) of the cantilever arms (13, 14) is provided on the carrier (4), and the cantilever arms (13, 14) as well as their swivel drive (16, 17) are linked to the rest (9).

What is claimed is: 
     
       1. A shield-advancing cutting machine for advancing a shield in an advancing direction having a longitudinal axis, said machine comprising: a generally cylindrical tubular shield having an inner circumferential surface and a leading circumferential edge;   means for axially advancing said shield in said advancing direction for maintaining proximity of said leading edge with a wall being mined;   a carrier means;   mounting said carrier means to said inner circumferential surface of said shield for selective movement along said longitudinal axis relative to said shield and for tilting movement relative to said longitudinal axis for providing said carrier means with a selectively varied angle of longitudinal axis inclination relative to said longitudinal axis of said shield;   a rest;   rotary drive means mounting said rest to said carrier means for selective rotary movement about the longitudinal axis of said carrier means;   a plurality of cantilever arms having rear ends pivotally mounted by swivel means to said rest so as to project axially forwards and radially outward from said rest;   control means mounted between each said cantilever arm and said rest for swiveling said arms about said swivel means;   said cantilever arms further having free forward ends provided with respective rotatable cutting heads, whereby said cantilever arms, when swivelled cause said rotatable cutting heads to be moved through respective arcs oriented generally transverse to said longitudinal axis of said carrier means;   said swivel axes of said rear ends of said cantilever arms being located at least two different distances radially away from said longitudinal axis of said carrier means; and   said axes of movement of respective ones of said cutting heads intersecting one another.   
     
     
       2. The shield-advancing cutting machine of claim 1, wherein: said rest comprises a radially extending plate fixed to an axially extending drive shaft;   said carrier means includes a support plate through which said drive shaft extends;   said rotary drive means comprises gear means on said drive shaft enmeshed with gear means on said support plate and motor means arranged in driving relation to at least one of said gear means; and   said swivel means pivotally mount said rear end of said cantilever arms to cheek members provided on said radially-extending plate.   
     
     
       3. The shield-advancing cutting machine of claim 2, wherein: said swivel means provide said rear ends of said cantilever arms with respective swivel axes disposed generally crosswise in relation to said longitudinal axis of said carrier means.   
     
     
       4. The shield-advancing cutting machine of claim 3, wherein: said swivel axes of said rear ends of said cantilever arms are located at least two different distances radially away from said longitudinal axis of said carrier means.   
     
     
       5. The shield-advancing cutting machine of claim 1, wherein: for each said cantilever arm, said cutting heads comprise two oppositely laterally-projecting mushroom-shaped cutting heads mounted for rotation about a common transversally-extending axis.   
     
     
       6. The shield-advancing cutting machine of claim 1, wherein: said leading circumferential edge is inclined downwardly-rearwardly as seen in side elevation; and   said carrier means mounting means is arranged for tilting said carrier means to such an extent that said longitudinal axes of said carrier means is approximately normal to said leading circumferential edge as seen in side elevation.   
     
     
       7. The shield-advancing cutting machine of claim 1, wherein: said axis of movement of respective ones of said cutting heads intersect.